Light and uncomplicated. These were designed for those who want to move really, really fast and those who think it's just plain crazy to carry heavy things around in the woods. A great blend of suspension, structure and weight conscious materials. Tough Stuff: The super-light 100D ripstop nylon pack body fabric is impregnated with silicone for waterproof strength that won't wear out or rub off over time. The heavier 420D nylon used for the pack bottom is just plain tough. Simple Comfort: Packs don't have to be complicated to be comfortable. The z-foam back panel and removable frame sheet are shaped to match the curve of your back. Nothing fancy. (Just lots and lots of prototypes.) Cool It: Poke the z-foam on the back panel (don't worry, it's tough stuff) and you'll see it springs back. That compression/ reaction motion happens as you hike, pumping air through to keep your back cool. Foam Sweet Foam: More foam does not equal more comfort. Super-plush belts and straps look comfy in the store but flatten out under pressure. Comfort happens when pressure is distributed evenly through good design and foam resilient enough to maintain volume under load. Keep It Clean: There was a time when packs were judged by how many zippers, buckles and straps they had. We're glad those days are over so we can concentrate on better ideas like daisy chains that tuck away when you donât need them.